1. Field of the Invention
The present invention relates generally to the field of waste containers lined with pet litter, and more specifically to a disposable waste container which absorbs liquids to prevent fermentation and odor, and has a cover with a middle section surrounded by perforations which tears away to leave a litter retaining lip.
2. Description of the Prior Art
Probably since the time people began bringing pets into their homes, and particularly cats, various forms of collection containers have been developed in which pets can bury their waste. These containers were probably first lined with soil and later with various types of absorbent litter.
One such container is disclosed in Neal, U.S. Pat. No. 4,441,451, issued on Apr. 10, 1984. Neal teaches a litter box apparently formed of paper or cardboard and folded together so that it has multiple layers to seal in moisture. Although Neal acknowledges the need for an absorbent box material, Neal teaches one that is "moisture proof." Thus, moisture not absorbed by the litter simply stands and ferments, causing odor. This shortens the useful life of the box, necessitating the inconvenience and expense of frequent replacement. Also, the litter can easily be spilled over the sides of the box while the cat is digging.
Another type of litter box is that of Cheesman, U.S. Pat. No. 4,553,671, issued on Nov. 19, 1985. Cheesman discloses a paperboard box having a litter containing compartment in its lower portion. The compartment is initially sealed under a paper cover. The center of the cover is torn out along perforations to expose the litter and to provide a retaining lip over the litter. A problem with Cheesman, like Neal, is that the box material is only slightly absorbent at most. In fact, Cheesman prefers a waterproof material. Thus liquids can remain and ferment. Another problem is that the retaining lip is near the bottom of the box. This limits the quantity of litter which can be retained in the box which in turn limits the useful life of the box.
Higgins, U.S. Pat. No. 4,541,360, issued on Sep. 17, 1985, includes a lower box member and a cover member which fits over the lower box member. To use the box, the middle of the cover member is torn out along perforations. This leaves an inwardly directed lip to retain litter. A problem with Higgins is that two boxes are actually required to create the retaining lip feature, one inverted and fit over the other. This duplication in materials also doubles the cost. Also, the material is not substantially absorbent, so the fermentation and odor problems are again presented.
Another variation is disclosed in Caldwell, U.S. Pat. No. 4,846,105, issued on Jul. 11, 1989. The Caldwell container is a cardboard box with top flaps that are opened and pointed upward. A rigid collar member is fitted around the flaps. The collar member is shaped to cause the tops of the flaps to converge and help retain scattered litter. A problem with Caldwell is that its cost not only includes the disposable box, but the reusable collar member as well. The collar member could become soiled with waste and, since it is reused, would have to be cleaned. Also, the cardboard box material is only marginally absorbent.
Elchenauer, U.S. Pat. No. 4,628,863, issued on Dec. 16, 1986, teaches a disposable litter box which folds from a closed container into an open box. When opened, Elchenauer is essentially a conventional litter box. Since Elchenauer is stated to be made of waterproofed cardboard, it has no absorbing ability. Also, no provision is made to prevent litter from spilling over the sides.
Another configuration is disclosed in Smith, U.S. Pat. No. 4,779,567, issued on Oct. 25, 1988. Smith includes a box and cover joined by hinges at one edge and having a handle at the opposite edge. Thus, Smith looks essentially like a suitcase. A litter bag is placed inside Smith and split open. The walls of Smith are described as moisture-resistant rather than as absorbent. Thus the problem of fermentation and odor remain. And again, no provision is made for keeping litter from scattering over the sides of the box.
Bella, U.S. Pat. No. 4,788,935, issued on Dec. 6, 1988, teaches a paperboard box structure contained within a bag. One wall of Bella remains exposed and has an entrance port for the cat. Bella thus contains odors within the box to some extent. A problem with Bella is that odors are concentrated within the box rather than absorbed. This may initially benefit humans, but drive the cat to defecate elsewhere. Also, litter can readily spill through the cat port when the cat digs and scatters it.
Zeitter, U.S. Pat. No. 3,886,901, issued on Jun. 3, 1975, discloses a box prefilled with litter which unfolds from a compact configuration. When unfolded for use, however, Zeitter is simply a conventional litter box. The box material is only slightly absorbent, and has no provision for retaining litter against scattering over its sides.
Much the same can be said of Sweeney, U.S. Pat. No. 3,154,052, issued on Oct. 27, 1964. Sweeney teaches a box which folds over itself to form a closed, compact container. Yet, like Zeitter, Sweeney becomes a conventional litter box when opened for use. The box is "moisture-resistant" rather than absorbent. Litter is not retained against spilling over the sides.
It is thus an object of the present invention to provide a pet litter box which absorbs liquid waste and thereby prevents fermentation and odor.
It is another object of the present invention to provide a pet litter box which retains litter against spilling over its sides when disturbed, without the addition of costly box structure.
It is still another object of the present invention to provide a pet litter box which is inexpensive, simple in design and easy to prepare for use.
It is finally an object of the present invention to provide a pet litter box which is constructed of recycled materials and thus benefits the environment.